The present disclosure relates to an apparatus and a method for controlling a direct-current (DC)-DC converter used in a vehicle.
Due to rapid increase of oil tax, automobiles increasing fuel efficiency have been released, for example, automobiles with idle stop & go (hereinafter, referred to as ISG) systems built therein.
ISG systems are not general starter motors of vehicles but integrated motors of starters and alternators, which operate as alternators while engines are operating. ISG systems, as described above, may be divided into an integrated type in which an alternator and a starter are formed as a single body and a separable type in which an alternator and a starter are separated from each other. However, configurations and operations thereof are similar. Accordingly, since ISG systems may be easily applied to engine automobiles, a demand thereof has increased.
FIGS. 1A and 1B are configuration views illustrating general starters of vehicles including an ISG system, respectively.
In FIG. 1A, the starter includes an input unit and output unit 11 and 15, in which flows of current occur, and a plurality of switches 12 and 14 and an inductor 13 for conduction of the input unit and output unit 11 and 15.
When a current flow occurs from the input unit 11 to the output unit, the input unit 11 may perform an input ripple removal function. Also, a plurality of switches 12a and 12b of a first switch unit part 12 may be driven as switches for a buck mode operation, and a plurality of switches 14a and 14b of a second switch part 14 and the inductor 13 may perform a switch function for a boost mode operation.
On the contrary, when a current flow occurs from the output unit 15 to the input unit 11, the plurality of switches 14a and 14b of the second switch part 14 may be driven as switches for the buck mode operation. In the case, the plurality of switches 12a and 12b of the first switch part and the inductor 13 may perform the switch function for the boost mode operation.
Also, in the case of FIG. 1B, similar to FIG. 1A, when a current flow occurs from an input unit 21 to an output unit 25, a plurality of switches 22a to 22f of a first switch part 22 perform a switch function for a buck mode operation. Also, a plurality of switches 23a to 23f of a second switch part 23 may perform a switch function for a boost mode operation.
On the contrary, when a current flow occurs from the output unit 25 to the input unit 21, the plurality of switches 23a to 23f of the second switch part 23 may be driven as switches for the buck mode operation. Also, a plurality of inductors 24a to 24c of the inductor 24 and the plurality of switches 22a to 22f of the first switch part 22 may perform the switch function for the boost mode operation.
The starter of the vehicle including the ISG system as described above may have a limitation such as heat generation caused by a configuration of the pluralities of switches and inductors and high conduction losses. In the case of such converter, a converter having high capacitance is not provided and a serial structure may be used in such a way that structural complexity of a control apparatus may occur.